API Ecosystems & Integrations

Connect applications, partners, workflows and AI agents through governed APIs

Sunesis helps organizations design, build and govern API ecosystems that connect internal teams, digital platforms, partner systems, enterprise applications, workflow engines and AI agents, combining API architecture, API management, integration engineering, Business APIs, event-driven patterns and cloud-native delivery.

We help organizations move from point-to-point integrations and fragmented APIs to governed API ecosystems that support digital products, partner collaboration, process automation and AgenticAI-ready architectures.

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Built for organizations that need secure, reusable and governed APIs across complex enterprise environments.

APIs are the foundation of modern digital ecosystems

Organizations increasingly depend on APIs that connect web and mobile applications, internal platforms, partners, developers, workflow engines and AI agents. APIs are how systems, teams and businesses collaborate.

But APIs create value only when they are designed, governed, documented, secured, monitored and reused. Without an API strategy, organizations end up with duplicated integrations, inconsistent contracts and unmanaged access.

Sunesis helps organizations build reliable, secure and manageable API ecosystems — from strategy and architecture to implementation and operations.

Sunesis designs API ecosystems where APIs become reusable, governed digital capabilities — not just technical endpoints.

From point-to-point integrations to reusable API ecosystems

Most enterprise landscapes accumulate one-off integrations over time. A governed API ecosystem replaces that complexity with reusable, managed and observable APIs.

Point-to-point integration

Custom integrations per project
Duplicated business logic
Inconsistent security and access control
Limited API visibility
Manual partner onboarding
Fragile dependencies
Not suitable for governed AI-agent access

Governed API ecosystem

Reusable APIs and Business APIs
Central API catalog and ownership
API gateway and access policies
Developer and partner onboarding
Lifecycle management and versioning
Usage visibility and monitoring
APIs prepared for applications, workflows and AI agents

What we build

We design and implement API ecosystems and integration architectures for organizations that need to connect complex systems, expose reusable capabilities and operate APIs securely at scale.

Enterprise API strategy and architecture

We help organizations define how APIs are designed, owned, versioned and governed, establishing an API-first foundation across teams and domains.

Key capabilities

API strategy
API domain modeling
API ownership models
API-first architecture
API lifecycle and versioning

API management platforms

We deliver the platform capabilities that make APIs discoverable, consumable and manageable across internal teams, partners and external developers.

Key capabilities

API catalog
Developer portal
API gateway
Access plans and subscriptions
Usage analytics

API gateway and access control

We implement the gateway layer that routes, secures and controls every API request, applying consistent policies across all consumers.

Key capabilities

Request routing and transformation
Authentication and authorization
OAuth2 and OIDC integration
Rate limiting and quotas
Gateway-level security

Business APIs and reusable capabilities

We expose repeated business functionality as reusable Business APIs, creating a governed capability layer between consumers and backend systems.

Example Business API domains

Customer and identity
Products and catalogs
Orders and payments
KYC and onboarding
Cases, tasks and notifications

Enterprise integrations

We connect APIs and Business APIs to core enterprise systems, legacy platforms and external services through robust integration architecture.

Integration areas

ERP and CRM
Core banking and insurance platforms
Document and case-management systems
Identity providers
Legacy systems and external APIs

Event-driven integrations

We design asynchronous, event-driven integrations that decouple systems, improve resilience and support real-time business flows.

Key capabilities

Kafka-based integration
NATS messaging patterns
Pub/sub and request-reply
Asynchronous processing
Event traceability

Partner APIs and API economy

We help organizations productize APIs for partners and external developers, enabling secure collaboration and new digital business models.

Key capabilities

Partner API strategy
API productization
Developer portal
Partner onboarding
Sandbox environments and access plans

AI-agent-ready APIs

We design APIs that AI agents can call safely, with clear contracts, validation and control boundaries built into the architecture.

Key capabilities

Agent-callable APIs
Tool-safe API design
API schemas for AI tool use
Gateway checks
Human approval boundaries

MCP-oriented API and tool integration

We expose APIs as governed tools for AI agents through MCP-oriented patterns, with policy enforcement and platform integration.

Key capabilities

MCP-oriented tool exposure
Tool metadata and schema design
API-to-tool mapping
Access and policy enforcement
Integration with KumuluzAI and Kumuluz API

API observability and lifecycle governance

We make APIs observable and governable across their lifecycle, giving teams visibility into usage, performance and dependencies.

Key capabilities

API usage monitoring
Performance metrics
Audit logs
Version management and deprecation
Consumer dependency visibility

Accelerated by Kumuluz API

Sunesis develops and delivers Kumuluz API, an API management and API economy platform that helps organizations expose, secure, monitor and govern APIs across teams, partners, applications and AI-agent-ready environments — with a catalog, developer portals, gateway, access control, sandbox, lifecycle governance and usage visibility.

Kumuluz API also supports AgenticAI scenarios, including MCP server patterns, contextual routing, LLM routing and token usage logging. On Sunesis projects, Kumuluz API accelerates ecosystem development and provides a reusable governance foundation.

Discovery

API catalog

A central catalog where APIs and Business APIs become discoverable, documented and owned across the organization.

Developers

Developer portal

Self-service onboarding, documentation, subscriptions and access plans for internal teams, partners and external developers.

Gateway

API gateway

Routing, transformation, authentication, authorization, rate limiting and policy enforcement for every API request.

Lifecycle

API lifecycle management

Versioning, deprecation, governance and lifecycle control so APIs evolve without breaking consumers.

Partners

Partner onboarding

Sandbox environments, subscriptions and access plans that make partner and API-economy collaboration secure and manageable.

AgenticAI

AgenticAI-ready API exposure

MCP server patterns, contextual and LLM routing and token usage logging that prepare APIs for safe AI-agent consumption.

Explore Kumuluz API

Business APIs turn repeated functionality into reusable capabilities

Business APIs encapsulate common business behavior behind clean, governed contracts. Instead of rebuilding the same logic in every project, teams consume a shared capability layer that protects backend systems and standardizes behavior across the organization.

Build once, reuse many times

Common business functionality is implemented once and reused across applications, partners, workflows and AI agents.

Standardize business behavior

Business rules and behavior become consistent across consumers instead of being reimplemented per integration.

Protect backend systems

Business APIs shield core systems behind a governed contract, decoupling consumers from backend complexity.

Enable workflow automation

Workflow engines call Business APIs as service tasks, turning reusable capabilities into automated process steps.

Prepare for AgenticAI

Business APIs become safe, governed tools that AI agents can call within clear policy and approval boundaries.

Improve API governance

A well-defined capability layer makes ownership, versioning and access control easier to manage at scale.

Integration architecture for complex enterprise landscapes

Real enterprise environments combine modern APIs, legacy systems, events, identity providers and workflow engines. Sunesis designs integration architectures that bring these together into observable, reusable and maintainable flows.

API-based integration

Synchronous integration through governed APIs and Business APIs with consistent contracts and access control.

Event-driven integration

Asynchronous integration through Kafka and NATS for decoupling, resilience and real-time flows.

Hybrid integration

A combination of synchronous APIs and event-driven patterns matched to each business flow.

Legacy system integration

Wrapping and exposing legacy platforms through APIs and adapters without disruptive rewrites.

Workflow integration

Connecting APIs and Business APIs to workflow engines such as Temporal and Camunda as service tasks.

Identity-aware integration

Integration flows that propagate identity, scopes and access policies across systems and consumers.

Observable integration flows

End-to-end visibility into integration flows through metrics, logs, traces and correlation IDs.

Reusable integration patterns

Standard, repeatable integration patterns that reduce duplication and accelerate delivery.

Prepare API ecosystems for AgenticAI

AI agents introduce a new class of API consumer. Sunesis designs API ecosystems where agents can call capabilities safely — through tool-safe contracts, gateway control, business-level tools and human approval boundaries.

Agent-callable APIs

APIs designed so AI agents can invoke them reliably with clear, well-documented schemas.

Tool-safe contracts

Contracts that constrain what an agent can do, with validation and safe defaults built in.

MCP-oriented integration

Exposing APIs as governed tools for agents through MCP-oriented patterns.

Gateway control

Routing agent calls through the API gateway for authentication, policy enforcement and logging.

Business APIs as tools

Reusable Business APIs that become governed, business-level tools for AI agents.

Workflow boundaries

Clear boundaries where agents prepare context and deterministic workflows execute process-critical steps.

Human approvals

Approval boundaries for sensitive or high-impact actions before they are executed.

Auditability

Traceability of agent API calls for operational, security and compliance purposes.

Security and governance across every API consumer

Whether an API is called by an application, a partner or an AI agent, the same governance principles apply. Sunesis builds security and governance into the API ecosystem so access, ownership and policy enforcement are consistent across all consumers.

API ownership

Clear ownership for every API, so responsibility, lifecycle and quality are well defined.

Access control

Consistent access policies, scopes and subscriptions across applications, partners and agents.

OAuth2 and OpenID Connect

Standards-based authentication and authorization integrated across the API ecosystem.

Partner governance

Onboarding, subscriptions, access plans and usage visibility for partner API consumers.

Agent governance

Policy enforcement and control over which APIs and tools AI agents are allowed to use.

Versioning and lifecycle

Version management, deprecation and lifecycle governance that protect existing consumers.

Policy enforcement

Centralized enforcement of security, rate limiting and access policies at the gateway.

Auditability

Audit logs and usage records for sensitive operations across the API ecosystem.

Make API and integration flows observable

You cannot govern what you cannot see. Sunesis instruments API ecosystems and integration flows so teams have full visibility into traffic, performance, usage and dependencies.

API traffic monitoringAPI latency and error metricsConsumer usage analyticsGateway logsDistributed tracingCorrelation IDs across APIs, events and servicesEvent flow observabilityPartner usage visibilityWorkflow-related API monitoringAgent API call tracingAudit logs for sensitive operationsOperational dashboards and alerting

Reference architecture for API ecosystems and integrations

A production API ecosystem separates API providers, integration, management, gateway, business capabilities, events, workflows and agent tools into clear layers — a more governable and maintainable architecture than direct point-to-point connections.

API providers

Internal services, enterprise systems and external services that provide the underlying APIs and data.

Integration and service layer

Services, connectors and integration logic that connect systems and expose capabilities.

Kumuluz API management layer

API catalog, developer portals, access control, lifecycle governance and usage visibility.

API gateway layer

Routing, transformation, authentication, authorization, rate limiting and policy enforcement.

Business API layer

Reusable Business APIs that expose governed business capabilities to all consumers.

Event and messaging layer

Kafka and NATS-based event flows for asynchronous, decoupled integration.

Workflow layer

Temporal, Camunda or similar engines that orchestrate deterministic business processes.

MCP and agent tool layer

MCP-oriented tools and agent-callable APIs that expose capabilities safely to AI agents.

API consumers

Web and mobile applications, partners, external developers, workflows and AI agents.

Observability and governance layer

Metrics, logs, traces, correlation IDs, usage analytics and audit trails across the ecosystem.

Where API ecosystems and integrations create value

API ecosystems and integrations create value wherever organizations need to connect complex systems, collaborate with partners or expose reusable capabilities at scale.

Enterprise API management

A managed foundation for exposing, securing, monitoring and governing APIs across the organization.

API catalogDeveloper portalGatewayAccess controlAPI lifecycleUsage analytics

Partner API ecosystem

Productized partner APIs with secure onboarding, documentation and usage visibility for the API economy.

Partner APIsSandbox environmentsSubscriptionsAPI documentationUsage visibilityAPI economy

Reusable Business API layer

A governed capability layer that abstracts backends and standardizes business behavior across consumers.

Business APIsCapability modelingBackend abstractionAPI governanceWorkflow-ready APIs

Enterprise integration platform

An integration architecture combining APIs, events and connectors across complex enterprise landscapes.

Integration architectureAPIsEvent-driven integrationConnectorsKafkaNATSObservability

AI-agent-ready API layer

An API layer prepared for safe AI-agent consumption through tool-safe design and gateway control.

Agent-callable APIsMCP-oriented toolsGateway controlTool-safe API designAuditability

Workflow-enabled API ecosystem

APIs and Business APIs connected to workflow engines as service tasks with full audit trails.

TemporalCamundaWorkflow APIsBusiness APIsService tasksAudit trails

Legacy API enablement

Wrapping legacy systems with APIs and adapters to modernize integration without disruptive rewrites.

Legacy wrappingAPI enablementIntegration adaptersSecurityLifecycle management

How we deliver API ecosystems and integrations

Assess the API and integration landscape

We review existing APIs, integrations, systems and pain points to understand the current state and opportunities.

Define the API strategy and governance model

We define how APIs are designed, owned, versioned, secured and governed across teams and domains.

Design the target integration architecture

We design the target architecture across APIs, Business APIs, events, gateway, workflows and observability.

Implement API management foundation

We set up the API catalog, developer portal, gateway, access control and lifecycle governance.

Build APIs, Business APIs and connectors

We implement the APIs, reusable Business APIs and integration connectors that the ecosystem needs.

Prepare for partners, workflows and AI agents

We enable partner onboarding, workflow integration and AI-agent-ready API consumption.

Add observability and lifecycle governance

We instrument monitoring, tracing, usage analytics, versioning and audit trails across the ecosystem.

Operate, evolve and scale

We support operations, continuous evolution and scaling of the API ecosystem over time.

Technology expertise

API architecture

REST, event-driven APIs, OpenAPI and API governance.

API management

Catalogs, developer portals, gateways, subscriptions and monitoring.

Integration

Enterprise integration patterns, connectors, legacy wrapping, cloud and partner integrations.

Events and messaging

Kafka, NATS, pub/sub, request-reply and event routing.

Service communication

REST, gRPC, protocol translation and gateway patterns.

Identity and security

OAuth2, OIDC, Keycloak, Microsoft Entra ID, scopes and policies.

Workflow integration

Temporal, Camunda, service tasks and process orchestration.

AgenticAI readiness

MCP-oriented tools, agent-callable APIs, tool-safe contracts and KumuluzAI integration.

Observability

Metrics, logs, traces, correlation IDs and API usage analytics.

Kumuluz platforms

Kumuluz API, Business APIs, Digital Platform and KumuluzAI.

API ecosystems and integrations in practice

Reference

Inorma — Zavarovalniška skupina Sava

An enterprise integration platform connecting systems across an insurance group, enabling reusable integrations and governed data flows.

Reference

KYC — NLB

Digital KYC and integrations supporting compliance and customer onboarding across banking systems.

Reference

NLB Klik

A digital banking solution with frontend and backend development and integrations across core banking systems.

Reference

EPUS — Plinovodi

A business-critical platform for energy infrastructure, combining workflows and integrations across enterprise systems.

Reference

CUPID

An open-source energy interoperability toolkit at LF Energy, enabling DER interoperability through shared, governed integrations.

Reference

Kumuluz API

An API management and API economy platform for exposing, securing, monitoring and governing APIs across teams, partners, applications and AI agents.

Explore our references

Why Sunesis for API ecosystems and integrations

We understand enterprise integration reality

We work with complex landscapes of modern systems, legacy platforms, partners and external services.

We combine API strategy with implementation

We define API strategy and governance and then build the APIs, Business APIs and integrations to realize it.

We bring API management capability

We deliver catalogs, developer portals, gateways, access control and lifecycle governance.

We design reusable Business APIs

We expose repeated business functionality as governed, reusable capabilities across the organization.

We support event-driven and API-first architectures

We combine synchronous APIs with Kafka and NATS event-driven patterns for resilient integration.

We prepare APIs for AgenticAI

We make APIs agent-callable and tool-safe, with gateway control and human approval boundaries.

We build for production

We deliver secure, observable and governed API ecosystems built to operate reliably at scale.

Need to build a governed API ecosystem?

Whether you are creating an API management foundation, exposing partner APIs, modernizing integrations, building reusable Business APIs or preparing APIs for AI agents, Sunesis can help you design, build and operate a secure and governed API ecosystem.

Start with API visibility and governance, then evolve toward partner ecosystems, workflow automation and AgenticAI-ready APIs.

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